Chapter 16 The Reproductive System Essentials of Human Anatomy & Physiology Seventh Edition Elaine N. Marieb Chapter 16 The Reproductive System Slides 16.1 – 16.20 Lecture Slides in PowerPoint by Jerry L. Cook Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Reproductive System Gonads – primary sex organs Testes in males Ovaries in females Gonads produce gametes (sex cells) and secrete hormones Sperm – male gametes Ova (eggs) – female gametes Slide 16.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Male Reproductive System Testes Duct system Epididymis Ductus deferens Urethra Accessory organs Seminal vesicle Prostate gland Bulbourethral gland External genitalia Penis Scrotum Slide 16.2a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Male Reproductive System Figure 16.2 Slide 16.2c Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Testes Each lobule contains one to four seminiferous tubules Function as sperm-forming factories Sperm travels through the rete testis to the epididymis Interstitial cells produce androgens such as testosterone Figure 16.1 Slide 16.3a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Epididymis Comma-shaped, tightly coiled tube Found on the superior part of the testis and along the posterior lateral side Functions to mature and store sperm cells (at least 20 days) Expels sperm with the contraction of muscles in the epididymis walls to the vas deferens Slide 16.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Ductus Deferens (Vas Deferens) Carries sperm from the epididymis to the ejaculatory duct Passes through the inguinal canal and over the bladder Spermatic cord – ductus deferens, blood vessels, and nerves in a connective tissue sheath Slide 16.6a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Ductus Deferens (Vas Deferens) Ends in the ejaculatory duct which unites with the urethra Vasectomy – cutting of the ductus deferens at the level of the testes to prevent transportation of sperm Slide 16.6b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Urethra Extends from the base of the urinary bladder to the tip of the penis Carries both urine and sperm Sperm enters from the ejaculatory duct Slide 16.7a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Seminal Vesicles Located at the base of the bladder Produces a thick, yellowish secretion (60% of semen) Fructose (sugar) Vitamin C Prostaglandins Other substances that nourish and activate sperm Slide 16.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Prostate Gland Encircles the upper part of the urethra Secretes a milky fluid Helps to activate sperm Enters the urethra through several small ducts Slide 16.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bulbourethral Glands Pea-sized gland inferior to the prostate Produces a thick, clear mucus Cleanses the urethra of acidic urine Serves as a lubricant during sexual intercourse Secreted into the penile urethra Slide 16.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Semen Mixture of sperm and accessory gland secretions Advantages of accessory gland secretions Fructose provides energy for sperm cells Alkalinity of semen helps neutralize the acidic environment of vagina Semen inhibits bacterial multiplication Elements of semen enhance sperm motility Slide 16.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

External Genitalia Scrotum Divided sac of skin outside the abdomen Maintains testes at 3°C lower than normal body temperature to protect sperm viability Slide 16.12 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

External Genitalia Penis Delivers sperm into the female reproductive tract Regions of the penis Shaft Glans penis (enlarged tip) Prepuce (foreskin) Folded cuff of skin around proximal end Often removed by circumcision Slide 16.13a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Spermatogenesis Production of sperm cells Begins at puberty and continues throughout life Occurs in the seminiferous tubules Slide 16.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Processes of Spermatogenesis Spermatogenesis takes 64 to 72 days Figure 16.3 Slide 16.17 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Anatomy of a Mature Sperm Cell The only human flagellated cell DNA is found in the head Figure 16.5 Slide 16.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Testosterone Production The most important hormone of the testes Stimulates reproductive organ development Underlies sex drive Causes secondary sex characteristics Deepening of voice Increased hair growth Enlargement of skeletal muscles Thickening of bones Slide 16.19a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Female Reproductive System Ovaries Duct System Uterine tubes (fallopian tubes) Uterus Vagina External genitalia Slide 16.21a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Female Reproductive System Figure 16.8a Slide 16.21b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Ovaries Composed of ovarian follicles (sac-like structures) Figure 16.7 Slide 16.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Ovarian Follicle Stages Ovulation – when the egg is mature the follicle ruptures Occurs about every 28 days Slide 16.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Uterine (Fallopian) Tubes Receive the ovulated oocyte Provide a site for fertilization Attaches to the uterus Does not physically attach to the ovary Slide 16.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Uterine Tube Function Fimbriae – finger-like projections at the distal end that receive the oocyte Cilia inside the uterine tube slowly move the oocyte towards the uterus (takes 3–4 days) Fertilization occurs inside the uterine tube Slide 16.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Uterus Located between the urinary bladder and rectum Hollow organ Functions of the uterus Receives a fertilized egg Retains the fertilized egg Nourishes the fertilized egg Slide 16.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Regions of the Uterus Body – main portion Fundus – area where uterine tube enters Cervix – narrow outlet that protrudes into the vagina Slide 16.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Walls of the Uterus Endometrium Inner layer Allows for implantation of a fertilized egg Sloughs off if no pregnancy occurs (menses) Myometrium – middle layer of smooth muscle Serous layer – outer visceral peritoneum Slide 16.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Vagina Extends from cervix to exterior of body Behind bladder and in front of rectum Serves as the birth canal Receives the penis during sexual intercourse Hymen – partially closes the vagina until it is ruptured Slide 16.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

External Genitalia (Vulva) Mons pubis Covered with pubic hair after puberty Labia – skin folds Labia majora Labia minora Figure 16.9 Slide 16.32a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

External Genitalia Vestibule Clitoris Enclosed by labia majora Contains opening of the urethra and the greater vestibular glands (produce mucus) Clitoris Contains erectile tissue Corresponds to the male penis Slide 16.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Oogenesis The total supply of eggs are present at birth Ability to release eggs begins at puberty Reproductive ability ends at menopause Oocytes are matured in developing ovarian follicles Slide 16.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Oogenesis Primary oocytes are inactive until puberty Follicle stimulating hormone (FSH) causes some primary follicles to mature Meiosis is completed after ovulation only if sperm penetrates Slide 16.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Oogenesis Figure 16.10 Slide 16.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings